i.MX8M Mini VPU and GPU Underclocking

[adamford]

I have an i.MX8M Mini where the the votlages for the VDD_VPU, VDD_GPU and VDD_DRAM are all tied together and operating at .95V so the LPDDR can run at 1.5GHz.

We're trying to lower power consumption by lowering the clocks of the VPU_H1 encoder and GPU which are both being used, but the datasheet for the i.MX8M Mini seems to show a voltage of 0.95V requires the GPU to run at 1000MHz and is too high to run the GPU at 800MHz.  The VPU_H1 seems to indicate we can run the VPU_H1 at 650MHz, but the VPU_PLL looks like it can go all the way down to 400MHz.

Can we safely underclock the VPU_H1 and 3D GPU to lower values without having to lower the DDR voltage of 0.95?

thank you,

Adam Ford,

Principal Applications Engineer, Beacon EmbeddedWorks.

[brian14]

Hi @adamford, 

Based on the Reference Manual for the iMX8M Mini the GPU clock for that voltage is up to 1000MHz therefore, you might underclock this block.

However, for VPU the target frequency for H1 acceleration is 800MHz. For this case, a lower clock might generate low performance.

Best regards, Brian.